The present invention is related to a foldable bearing structure for moulding outer surfaces of vertical walls and their continuous or partial perimetric overhangs, in the shape of balconies and such like, provided with planes adapted to receive modulated sheets which, apart from being resistant, are capable of being provided with embossments, channels, etc. constituting utilitarian decorations, and, at the edges, sheets constituting sides of columns and bottoms of necks between the walls and the overhangs.
Removable structures for this purpose are known, but they are, as a rule, heavy, costly and difficult to handle in order to be brought to and removed from construction sites as well as to be mounted thereon.
The essence of the present invention resides in that the structure in question is light, its cost is relatively much lower than that of the known embodiments performing a similar task, and its weight does not require, as in the prior structures, elevator cranes or special transportation trucks, but it may be carried by conventional general purpose trucks and loaded onto or removed from the same at the site by a few workmen if trucks are used which do not carry their own loading and unloading equipment.
At the ends of its vertical wings this novel structure carries sheets constituting columns in such a way as to complete the inner moulds used jointly with these structures, and, moreover, it includes a rigid portal at the center of the span between the walls. In this way they bar efficiently the wings of the inner moulds and complement them.
An important feature of the structures in accordance with the present invention is characterized in that they are universal, i.e. they are capable of forming protruding angles (or corners) as well as inner angles, by removing the inner supplement whenever necessary. Likewise, they are capable of forming uninterrupted series where the project requires such constructions.
Another important feature is that they can be hoisted up onto and lowered from upper floors with the aid of conventional means, manual or motorized equipment, which exists at every site in order to hoist up or lower materials as, for instance, doors, windows and such like, and to pass through apertures practically of the same size as the minimum required for passing through the doors and windows.
An exemplary embodiment of the bearing structure for outer moulding surfaces according to the invention, includes a rigid central portal constituted by a main post, to the ends of which are fixed, on one and the same side, horizontal, coplanar upper and lower beams having their free ends secured diagonal stays at a point intermediate the main post. Two side frames are hinged by means of their vertical sides one on either side of the main post, to the horizontal sides of which frames are joined a plurality of removable secondary portals, similar to the rigid central portal and adapted for sustaining each an upper rectangle hinged by means of their smaller sides to said upper beam. A right-angled triangle is joined to each of the lower horizontal sides of the side frames, by means of their larger legs, while the smaller leg is adapted for nesting in channels provided in the said lower beam.